<html>
<head><meta charset="utf-8"><title>weekly meeting 2018-11-26 · wg-traits · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/index.html">wg-traits</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html">weekly meeting 2018-11-26</a></h3>

<hr>

<base href="https://rust-lang.zulipchat.com">

<head><link href="https://rust-lang.github.io/zulip_archive/style.css" rel="stylesheet"></head>

<a name="148389687"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148389687" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148389687">(Nov 26 2018 at 19:06)</a>:</h4>
<p>Hello <span class="user-group-mention" data-user-group-id="692">@WG-compiler-traits</span> <span class="emoji emoji-1f44b" title="wave">:wave:</span></p>
<p>As always: <a href="https://paper.dropbox.com/doc/WG-Traits-Planning-Meeting--ALDA5111ZliLv5zlSgbjvDS2Ag-oDfr6ct8xx63HSAOOmIZX" target="_blank" title="https://paper.dropbox.com/doc/WG-Traits-Planning-Meeting--ALDA5111ZliLv5zlSgbjvDS2Ag-oDfr6ct8xx63HSAOOmIZX">Dropbox paper doc</a></p>
<p>Also, a note: If you want to be added to the <span class="user-group-mention" data-user-group-id="692">@WG-compiler-traits</span> alias, just ask.</p>



<a name="148390094"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148390094" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148390094">(Nov 26 2018 at 19:10)</a>:</h4>
<p>BTW, <span class="user-mention" data-user-id="131694">@scalexm</span>, awesome news about getting the first chalk example to run!</p>



<a name="148390209"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148390209" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148390209">(Nov 26 2018 at 19:12)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> I got more complex programs to run than this one actually</p>



<a name="148390220"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148390220" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148390220">(Nov 26 2018 at 19:12)</a>:</h4>
<p>example?</p>



<a name="148390224"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148390224" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148390224">(Nov 26 2018 at 19:12)</a>:</h4>
<p>but there are some unknowns that we should discuss</p>



<a name="148390276"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148390276" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148390276">(Nov 26 2018 at 19:13)</a>:</h4>
<p>things like</p>
<div class="codehilite"><pre><span></span><span class="k">trait</span><span class="w"> </span><span class="n">Foo</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="p">}</span><span class="w"></span>
<span class="k">impl</span><span class="o">&lt;</span><span class="n">T</span><span class="o">&gt;</span><span class="w"> </span><span class="n">Foo</span><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">i32</span><span class="p">,</span><span class="w"> </span><span class="n">T</span><span class="p">)</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="p">}</span><span class="w"></span>

<span class="k">fn</span> <span class="nf">foo</span><span class="o">&lt;</span><span class="n">T</span>: <span class="nc">Foo</span><span class="o">&gt;</span><span class="p">()</span><span class="w"></span>

<span class="k">fn</span> <span class="nf">main</span><span class="p">()</span><span class="w"> </span><span class="p">{</span><span class="w"></span>
<span class="w">    </span><span class="n">foo</span>::<span class="o">&lt;</span><span class="p">(</span><span class="kt">i32</span><span class="p">,</span><span class="w"> </span><span class="kt">u32</span><span class="p">)</span><span class="o">&gt;</span><span class="p">();</span><span class="w"></span>
<span class="w">    </span><span class="n">foo</span>::<span class="o">&lt;</span><span class="p">(</span><span class="kt">u32</span><span class="p">,</span><span class="w"> </span><span class="kt">u32</span><span class="p">)</span><span class="o">&gt;</span><span class="p">();</span><span class="w"> </span><span class="c1">//~ ERROR</span>
<span class="p">}</span><span class="w"></span>
</pre></div>



<a name="148390297"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148390297" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148390297">(Nov 26 2018 at 19:13)</a>:</h4>
<p>or with super traits, projections etc</p>



<a name="148390309"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148390309" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148390309">(Nov 26 2018 at 19:13)</a>:</h4>
<p>well basically WF-checking seems to work</p>



<a name="148390371"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148390371" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148390371">(Nov 26 2018 at 19:14)</a>:</h4>
<p>implied bounds work too which is funny :p</p>



<a name="148390525"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148390525" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148390525">(Nov 26 2018 at 19:17)</a>:</h4>
<blockquote>
<p>implied bounds work too which is funny :p</p>
</blockquote>
<p>:) I guess that's expected</p>



<a name="148390764"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148390764" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148390764">(Nov 26 2018 at 19:19)</a>:</h4>
<p>we're a chatty bunch this week :)</p>



<a name="148390778"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148390778" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148390778">(Nov 26 2018 at 19:20)</a>:</h4>
<p>so <span class="user-mention" data-user-id="131694">@scalexm</span> I guess the current status from your side is that we need to look at that perf regression, and I need to review your PR</p>



<a name="148390899"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148390899" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148390899">(Nov 26 2018 at 19:21)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> yes</p>



<a name="148391172"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148391172" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148391172">(Nov 26 2018 at 19:24)</a>:</h4>
<p>ok</p>



<a name="148391178"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148391178" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148391178">(Nov 26 2018 at 19:24)</a>:</h4>
<p>mmh <span class="user-mention" data-user-id="116009">@nikomatsakis</span> I see a failure on your universes PR</p>



<a name="148391209"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148391209" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148391209">(Nov 26 2018 at 19:24)</a>:</h4>
<p>indeed</p>



<a name="148391211"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148391211" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148391211">(Nov 26 2018 at 19:24)</a>:</h4>
<p>needs a bless run</p>



<a name="148391255"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148391255" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148391255">(Nov 26 2018 at 19:25)</a>:</h4>
<p>we should also discuss whether to modify the canonicalizer behavior w/r/t region variables I guess</p>



<a name="148391256"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148391256" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148391256">(Nov 26 2018 at 19:25)</a>:</h4>
<p>also depends on whether we might want to back out the change in the placeholders PR :p</p>



<a name="148391267"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148391267" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148391267">(Nov 26 2018 at 19:25)</a>:</h4>
<p>yes</p>



<a name="148391294"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/148391294" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#148391294">(Nov 26 2018 at 19:25)</a>:</h4>
<p>I'd be inclined to start by putting all existentials in root universe, maybe unless <code>-Zuse-chalk</code> or whatever is given</p>



<a name="150775646"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/150775646" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#150775646">(Dec 03 2018 at 14:57)</a>:</h4>
<p>FYI I’ve been interviewing last week and this week, so I won’t make the meeting today.</p>



<a name="150784507"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/150784507" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#150784507">(Dec 03 2018 at 17:14)</a>:</h4>
<p>Hey, probably won’t be able to make today’s meeting either, I’ll update Dropbox notes</p>



<a name="150784571"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-26/near/150784571" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-26.html#150784571">(Dec 03 2018 at 17:15)</a>:</h4>
<p>Meanwhile please note that I have opened chalk-integration PR</p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
</html>